Thunder Emperor Card Pack

The Thunder Emperor Card Pack is a card pack that accompanied the event Fullmoon Party - Sacred Tree of Heaven. It was available from December 3 up to December 18, 2012, but it was extended to the 19th.

Drawing 10 cards from the Thunder Emperor Card Pack or from the Yell Card Pack will allow you to fight one of the three bosses. The total damage done to any one of them will place you in a ranking, earning you appropriate rewards if you're in the top 100.